Retrieving data for relative altitude and air pressure with CMAltimeter

AltitudeViewController.swift

//
//  AltitudeViewController.swift
//  Altitudes
//
//  Created by Taylor Franklin on 10/22/14.
//

import UIKit
import CoreMotion

class AltitudeViewController: UIViewController {
    
    @IBOutlet weak var altitudeLabel: UILabel!
    let altimeter = CMAltimeter()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func start(sender: AnyObject) {
        
        if CMAltimeter.isRelativeAltitudeAvailable() {
            altimeter.startRelativeAltitudeUpdatesToQueue(NSOperationQueue.mainQueue(), withHandler: { data, error in
                if (error == nil) {
                    println("Relative Altitude: \(data.relativeAltitude)")
                    println("Pressure: \(data.pressure)")
                }
            })
        }
        
    }

}